Justification:
Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.

The species' range extends from southern California, southern Nevada, and southwestern Utah south through Arizona (Lowe et al. 1986), southern New Mexico (Degenhardt et al. 1996), western Texas (Tennant 1984) in the United States, and central Mexico to near the south end of the Mexican Plateau in Puebla and adjacent Veracruz (Stebbins 2003, Campbell and Lamar 2004). Its elevational range extends from sea level to around 2,530 m asl (8,300 feet) (Stebbins 2003); above 1,800 m asl at the southern end of the range (Campbell and Lamar 2004).

This species is represented by a large number of occurrences (subpopulations). On a range-wide scale, Campbell and Lamar (2004) mapped hundreds of collection sites. The adult population size is unknown but presumably exceeds 100,000. This snake is often locally common (Lowe et al. 1986). Its extent of occurrence, area of occupancy, number of subpopulations, and population size are probably relatively stable.

The species' habitat is mostly upland desert and lower mountain slopes, including barren desert, grassland, open woodland, and scrubland; in the United States, vegetation in most occupied areas includes creosote bush, palo verde, mesquite, or cacti (Ernst 1992, Ernst and Ernst 2003, Stebbins 2003, Campbell and Lamar 2004). This snake usually is not in broken rocky terrain or densely vegetated areas. In southeastern Arizona, it is more numerous in semi-desert grassland than in desert scrub (Mendelson and Jennings 1992). In southern Arizona and adjacent Mexico, it is very common in prairie valleys between forested mountain ranges (Armstrong and Murphy 1979). In the southern part of the range in Mexico, it occurs in open high interior plains, mesquite-grassland, pine-oak, and lava beds with cactus, agave, and grasses (Armstrong and Murphy 1979). In spring, this snake commonly coils under a small tree or shrub in early morning (Armstrong and Murphy 1979). Refuges include animal burrows, spaces under or among rocks, or similar sites.